The present invention relates to an opening device for an open-end spinning apparatus which includes a housing. In the interior space of the housing is arranged an opening roller and an insert which accommodates the opening roller and which exhibits perforations, enclosed on all sides, which correspond to housing orifices connecting the interior space with other parts of the spinning apparatus.
It is known from German Offenlegungsschrift No. 2,427,333 to provide an insert in an opening roller housing for its protection. This insert is not elastically deformable and, therefore, only suitable for a circular construction of the housing interior space. If the interior space provided in the insert is required to be noncircular, then this is only possible by machining. The orifices provided in the insert can also be produced only by machining. However, this insert is relatively expensive to produce, has a large space requirement and also requires bulky opening roller housings.
Thin-walled foils which are stuck onto the walls opposite the circumference of the opening roller are also known from German Offenlegungsschriften Nos. 2,423,241 and 2,448,585. However, the adhesive joints cannot be released without difficulty when required. In order to avoid gluing in the foil, it is also known to tension the foil and to fix it in the tensioned state to the housing (German Offenlengungsschriften No. 2,819,060 and 2,911,158). This is done with the aid of a tensioning wedge (German Offenlegungsschrift No. 2,819,060) or of a subsequently hardenable filler (German Offenlegungschrift No. 2,911,158). In both cases, a small gap is present between the ends of the foil, on which individual fibers which have not succeeded in detaching themselves from the opening roller in the region of the fiber feed duct, can catch and accumulate. Such accumulation of fibers causes compression and tangling of these fibers. When this accumulation of fibers is subsequently torn away from the gap region by the opening roller, they enter the spinning rotor with the other fibers and form an imperfection there, or at least an irregularity in the yarn.
It is, therefore, the aim of the present invention to produce an insert for an opening device which is free from the disadvantages described but which is economical to produce, economical in terms of space and quickly exchangeable.